Hi, Jean Delvare wrote: > [Don't forget to CC: the mailing list on replies please] Well, all mails so far, have had a reply-to address. Just the last one had not. I'll have to be more careful then ;-) >>>>Basically this means the following conversion table, if I'm not >>>>mistaking: >>>>0..2 -> 1 (div=2) >>>>3..4 -> 2 (div=4) >>>>5+ -> 3 (div=8) >> >>I don't think, that this a good idea. If you recall an email from me >>about VERAX fans, which supply 9 times as many pulses per rotation as >>normal fans do, those fans would require a div of 18. This value would >>then silently be converted to div = 8 and results in less then one >>halve of the actual fan rpm. >> >>In my opinion, the driver should complain about any div values it >>doesn't support, and simply do nothing as it wouldn't be what the user >>expected, anyway. Therefore, once again the question: How should the >>driver inform about/react on unsupported div values? > > Well, this makes sense, you're right. You get the point. > > In my mind, there was no possibility to return an error code, so you had > to accomodate the best you could with the input, and keep quiet. By the > way, what does conretely happen if you try to write a wrong value to the > sysfs file? video:/soft/src/lm_sensors2/kernel/chips # cat \ /sys/bus/i2c/devices/0-0073/fan_div1 2 video:/soft/src/lm_sensors2/kernel/chips # echo 1 > \ /sys/bus/i2c/devices/0-0073/fan_div1 video:/soft/src/lm_sensors2/kernel/chips # cat \ /sys/bus/i2c/devices/0-0073/fan_div1 2 video:/soft/src/lm_sensors2/kernel/chips # Nothing special. The invalid value is simply ignored. Although set_fan_div() returns -1 in that case, echo doesn't show any error. How about adding a printk() for that case? Bye. -- Dipl.-Inform. (FH) Reinhard Nissl mailto:rnissl at gmx.de
